I bought a 4Mbit EEPROM some time ago with the intent of making it into a Master System flashcart and today I was finally able to dump it:



They gave me an used chip! And I can't write to it because it's probably locked!
The chip is an AT29C040A, here's the datasheet: https://www.futurlec.com/Memory/AT29C040.shtml

Who wants to write some software for my homemade burner/dumper so I can unlock this? I made it based on MEEPROMMER but with an extra shift register to accommodate the extra address lines since my chip is larger than what that was designed for.

This is a picture of my rig:


I've been trying this fork of the original code: https://github.com/Skidlz/MEEPROMMER
It seems to have the unlock code already in the Arduino firmware but it doesn't seem to work.

SO WHO WANTS TO HELP ME?

cut the blue wire

NEVER cut the blue wire!

I would like to help but I think this is pretty far beyond any of us here

Technical stuff kid

you need a new keyboard, that one looks terrible

yeah the wasd keys aren't even red

it's a cheap usb keyboard that has survived for an absurd long time

the black spots you see where the hands rest is where the gray paint faded away

you can first check the boot lockout ?? if thats the problem.

BOOT BLOCK LOCKOUT DETECTION:
A software method is available to determine whether programming of
either boot block section is locked out. See Software Prod-
uct Identification Entry and Exit sections. When the device
is in the software product identification mode, a read from
location 00002H will show if programming the lower ad-
dress boot block is locked out while reading location FFFF2H will do so for the upper boot block. If the data is
FE, the corresponding block can be programmed; if the
data is FF, the program lockout feature has been activated
and the corresponding block cannot be programmed. The
software product identification exit mode should be used
to return to standard operation

Do you have issues with the full addressing? (19bit)

just order a new one from digikey

that way they'll send you their gargantuan catalog that takes an entire tree to make every few months

HEY IT WORKS NOW AFTER A LOT OF WORKING ON IT

you can first check the boot lockout ?? if thats the problem.

I wasn't sure how to write the unlock codes, a friend help me with those

just order a new one from digikey

that way they'll send you their gargantuan catalog that takes an entire tree to make every few months

I don't think they ship to Brazil and if they do it'll be too expensive

Anyway here
http://mynameiser.in/post/93905395896/after-3-days-of-struggling-with-arduino-c-and

i made a cool write-up maybe i'll be feature on hack-a-day!!!

http://mynameiser.in/post/94106321451/i-figured-the-eeprom-burner-deserved-a-proper

How many people in Brazil have even done that??? That's amazing!

How many people in Brazil have even done that??? That's amazing!

I know only one or two other people who do stuff like this, but I guess they just don't show off their stuff on the internet as much

really fetching cool